FILE – In this March 24, 2018 file photo, protesters fill Pennsylvania Avenue, as seen from the Newseum, during the “March for Our Lives” rally in support of gun control in Washington. Rachel Einwohner, a Purdue University sociology professor, says, “With the rise of social media, it’s definitely a lot easier for people to mobilize more quickly and you don’t necessarily need to have one charismatic leader like Dr. King, who had almost some kind of magical quality… But you still do need some powerful message that really resonates with a lot of people.” (AP Photo/Jose Luis Magana